Method: NewRelic::Agent::SystemInfo.docker_container_id

Defined in:
lib/new_relic/agent/system_info.rb

.docker_container_id ⇒ Object

When operating within a Docker container, attempt to obtain the container id.

First look for ‘/proc/self/mountinfo` to exist on disk to signify cgroups v2. If that file exists, read it and expect it to contain one or more “/docker/containers/<container_id>/” lines from which the container id can be gleaned.

Next look for ‘/proc/self/cgroup` to exist on disk to signify cgroup v1. If that file exists, read it and parse the “cpu” group info in the hope of finding a 64 character container id value.

For non-cgroups based containers, use a ‘nil` value for the container id without generating any warnings or errors.

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# File 'lib/new_relic/agent/system_info.rb', line 205

def self.docker_container_id
  return unless ruby_os_identifier.include?('linux')

  cgroupsv2_based_id = docker_container_id_for_cgroupsv2
  return cgroupsv2_based_id if cgroupsv2_based_id

  cgroup_info = proc_try_read('/proc/self/cgroup')
  return unless cgroup_info

  parse_docker_container_id(cgroup_info)
end